This invention relates to a shredder and more particularly to the control of rate at which documents are supplied to a shredder.
Prior art shredders are provided with only one intake section for accepting documents to be shredded. If it happens that a certain document must be shredded immediately while such a shredder is in the midst of shredding a large number of documents continuously, the operator must either interrupt the job currently in progress and start the more urgent shredding job or wait until the job in progress is completed and then start the required urgent job, and there is a loss of time in either way. If the person in possession of such a document decides to leave it with the operator, asking the operator to shred it as soon as the job in progress is completed, there is the danger of the secret leaking in the meantime. On the other hand, it is not economical from the point of view both of cost and of space to provide more than one shredder. In view of this disadvantage of prior art shredders, the present applicant has previously considered a shredder having a plurality of intake sections as disclosed in Japanese Patent Application No. 61-105878. According to an embodiment of the technology disclosed therein, the cutter rollers have the capability of shredding 22 sheets and the numbers of sheets supplied through the first and second intake sections are controlled to be 15 or less and 7 or less, respectively. Thus, even if documents are transported simultaneously through the two intake sections, no more than 22 sheets of paper will be supplied to the cutter rollers simultaneously in excess of their capability and all sheets that are supplied are successfully shredded. A shredder thus controlled, however, is not efficient if only one of the intake sections is used to feed documents because no more than 15 sheets are actually shredded although the cutter rollers are capable of shredding up to 22 sheets.